Datalogic SG4 FIELDBUS Series, Instruction Manual, Page: 14 / 136

GENERAL INFORMATION
4 SG4 EXTENDED
HOW TO CHOOSE THE DEVICE
There are at least three different main characteristics that should be considered when
choosing a safety light curtain, after having evaluated the risk assessment.
Detection capability
The detection capability (or resolution) of the device is the minimum diameter that an
opaque object must have in order to obscure at least one of the beams that constitute
the detection zone and to actuate the sensing device.
The resolution is related to the part of the body to be protected.
R = 14 mm Finger protection
R = 30 mm Hand protection
As shown in Figure 1 the resolution only depends on the geometrical characteristics of
the lenses, diameter and distance between centers, and is independent of any environ-
mental and operating conditions of the safety light curtain.
Figure 1 - Detection capability
The resolution value is obtained applying the following formula:
R = I + d
where:
I = Interaxes between two adjacent optics
d = Lens diameter